The Energy Cost of Cooking Dinner for Two, Measured

Our electricity bill rose by 18 pounds between October and November last year and nothing obvious had changed. Same flat, same two people, same thermostat left at 18.5 degrees. I went through the spreadsheet line by line looking for a new subscription or a meter reading error, and the only thing that had really moved was how often the oven came on. The weather turned, we started roasting things again, and the bill followed.

So I did what I should have done in our first winter here. I bought a plug in energy monitor for 14 pounds, and for five weeks I logged the actual consumption of every dinner we cooked. Not estimates from a manufacturer leaflet. Readings, in a column, next to the meal. The totals were smaller than I expected and spread out in a way that made most of the kitchen advice I had read look sloppy.

How we measured it, and what the numbers leave out

The plug monitor handled the air fryer, the microwave, the kettle and the slow cooker. The fan oven and the induction hob are wired into their own circuit, so for those I took a whole flat meter reading, cooked one dish with everything else in the flat switched off at the socket, then read the meter again. Clumsy, but repeatable within about 0.03 kWh across three attempts.

Our unit rate at the time was 24.5 pence per kWh. I left the daily standing charge out of every figure here, because it arrives whether we cook or order a takeaway, so folding it into a per meal cost would only flatter whichever appliance we used least.

One honest limit before the table. I cannot tell you what your oven draws. Ours is a 2.4 kW fan oven fitted around 2014, and a newer one with better door insulation will read lower on the same recipe. The method here transfers cleanly. The numbers do not.

What one dinner for two actually costs to cook

These are median readings from the log, rounded to the nearest penny, for portions sized for two people.

Across the five weeks, cooking came to roughly 4.60 pounds a month. That is less than one supermarket meal deal each. It also means the whole category is a poor place to look for a dramatic saving, which is worth saying out loud before anyone spends money chasing one.

The air fryer saving is mostly a story people repeat

I went into this expecting the air fryer to be the hero. It is the appliance friends keep telling us has halved their bill. Our log says something duller.

Against the oven on the same food, the air fryer saved 23 pence a meal. If we had swapped every single oven dinner for an air fryer dinner, five nights a week, that is 1.15 pounds a week, or about 60 pounds across a year. A respectable number until you remember that the machine cost 89 pounds, so the payback sits somewhere past the eighteen month mark, and only if the swap is total.

It never is. The 5.5 litre basket will not hold a tray of potatoes and a tray of vegetables for two at the same time without crowding them into something steamed and grey. So we run it twice, 22 minutes and then 20 minutes, which lands at roughly 0.9 kWh and erases most of the gap. On Sunday, when we are cooking anything that feeds us twice, the oven wins outright on cost per portion because it is already hot.

The air fryer earns its counter space on speed and on not heating the kitchen in July. Those are real benefits. They are just not the ones written on the box, and we had already made the same mistake with a different gadget, which is part of why we now argue about every purchase over 40 pounds before it enters the flat. Our notes on which gadgets survived are in the small kitchen tools worth the counter space.

Three habits that did move the number

Skip the preheat on anything slow

Preheating matters for a cake or a pizza base, where the first four minutes decide the texture. For a tray of root vegetables that will sit in there for 45 minutes, it does almost nothing except burn 0.38 kWh before the food arrives. We stopped preheating for slow roasts and added about four minutes to the cook time. Measured saving, 9 pence a time, roughly 1.80 pounds a month at our frequency.

Never heat an oven for one tray

If the oven is on at 200C, the second shelf is nearly free. We now plan Wednesday and Thursday dinner as one oven session: chicken thighs on the top shelf, a tray of squash underneath that becomes the next night's base. Two dinners for 1.42 kWh instead of 2.84. This is the single biggest line in the whole experiment and it cost nothing to adopt.

Lids, and the kettle instead of the pan

Two litres of water reached a rolling boil in 5 minutes 40 seconds with a lid on and 9 minutes 10 without. Starting pasta water in the kettle and tipping it into the pan cut it further. Small amounts, a few pence a week, but the habit is free and the kitchen stays less humid, which matters in a flat where we already fight condensation.

The appliance nobody puts on a spreadsheet

Here is the result that reframed the whole exercise for me. I left the monitor on the fridge freezer for nine days and it averaged 0.94 kWh a day. That is 23 pence daily, about 84 pounds a year, which is more than every pan, oven and gadget in the flat combined.

Nothing about that is fixable with a recipe change, but two things helped. The door seal failed the paper test on the lower hinge side, where a banknote slid out with no resistance at all, so the landlord replaced the gasket. And the freezer had built up about 9 millimetres of ice on the back wall. Defrosting it took an afternoon and dropped the daily average to 0.81 kWh. That is 11 pounds a year from one boring Saturday.

If you only do one thing after reading this, do the paper test on your fridge door rather than rearranging your cooking. It took me three winters of logging kitchen energy to work out that the cooking was never the expensive part. The same pattern showed up when we went through the heating, which I wrote about in how we cut our energy bill in a rented flat.

FAQ

Is a slow cooker cheaper than an oven?

Usually yes, at 21 pence against 35 for our comparable meals, though the gap is narrower than most people assume because the slow cooker runs for seven hours. It wins clearly on cheap cuts of meat, which is where the real saving sits, in the shopping rather than the socket.

Does a gas hob cost less to run than induction?

Per unit of energy, gas is cheaper, but induction puts far more of what it draws into the pan. We have no gas in this flat so I have no readings of my own, and I would not trust a figure I had not measured myself.

How much does a plug in energy monitor cost?

We paid 14 pounds for a basic one with a kWh total and a cost field. It paid for itself on the fridge finding alone. Avoid the versions that only show instantaneous watts, because you need the running total to compare a whole meal.

Should I replace an old oven to save on energy?

On our numbers, no. At roughly 4.60 pounds a month for all cooking, even a 30 percent efficiency gain returns under 17 pounds a year, and a new oven is several hundred. Replace it when it stops holding temperature, not as a saving. We think through purchases like this the same way we handle the food budget for two, by asking what the monthly line actually is first.